Empty values in array creation should be not set

[galpeter]

When creating arrays it is possible to set 'empty' values
which are not undefined, but simply unused values.

JerryScript-DCO-1.0-Signed-off-by: Peter Gal pgal.u-szeged@partner.samsung.com

[galpeter]

One related test262 testcase: https://github.com/tc39/test262/blob/es5-tests/test/suite/ch15/15.2/15.2.3/15.2.3.7/15.2.3.7-6-a-155.js

[zherczeg]

+1 lgtm

[ruben-ayrapetyan]

I think, this should be fixed by modification of byte-code / opcode handlers, without introduction of a new simple value.

[ruben-ayrapetyan]

Is there any issue opened for this?

[galpeter]

@ruben-ayrapetyan , there is no issue opened for this. I'll create one.

I've got one question regarding the byte-code/opcode way: in the ecma_op_create_array_object method how would the 'unset' arguments appear? (Currently) In that function we need to know which indexes are set, and which are not.

[galpeter]

Created issue: #356

[ruben-ayrapetyan]

@galpeter, thank you!

ECMA-262 v5, 11.1.4 defines that array object should be created empty, and then filled, step by step. So, we don't need to pass 'unset' arguments to ecma_op_create_array_object.

[galpeter]

So that means that we the ecma_op_create_array_object will be called with empty argument list and then the elements will be added one by one (via define prop or something like that). If so then we can close this PR.

[egavrin]

@galpeter @ruben-ayrapetyan let's close this PR is everyone is OK to continue with #356.

[ruben-ayrapetyan]

@galpeter, @egavrin, I agree that the pull request can be closed, as the issue is already described in #356 with reference to the pull request.

[egavrin]

Ok.